Mechanical Engineering Commons^™

The Passive Load-Bearing Capacity Of The Human Lumbar Spine In The Neutral Standing Posture, Shaun B. Jeffs

Theses and Dissertations

The human lumbar spine has been shown to support compressive loads of 1000 N in standing and walking, and up to many thousands of Newtons in strenuous activities such as lifting. The literature presents a number of biomechanical models that seek to replicate the load-carrying capacity of the spine while adhering to physiological constraints. While many of these models provide invaluable insights into the mechanisms governing spinal stability, there is a nearly universal disregard for the magnitude of the muscle forces required in the neutral standing posture. In compliance with constraints on metabolic cost and muscle fatigue, muscle activations in …

Soap Bubbles And Solid Spheres: Collisions And Interactions, Joshua A. Bryson

Theses and Dissertations

Under the right conditions, a moving sphere may successfully enter, and leave, a soap bubble without rupturing that bubble. The physics behind this phenomena are not well understood, nor the limiting factors (such as sphere size, speed, etc.). This work, investigating this phenomenon using high speed photography, has produced several results which are presented. First, several distinct regimes, noted while photographing the interactions between the spheres and the bubbles, are classified and discussed. Next a probabilistic examination of the soap bubbles rupture by the moving spheres is presented. Then a conjecture for the limiting sphere sizes and speeds is presented. …

Control System For Mass Spectrometer, Jian Xu

Purdue Polytechnic Masters Theses

Mass spectrometry (MS) is a very popular analytical methodology that measures the mass of ions using a mass spectrometer. It is widely used for determining masses of chemicals, the elemental composition of a sample and molecule structure. The process of mass spectrometry normally consists of ionizing chemical compounds to ions and measuring their ratios of mass to charge for analysis.

MS instruments consist of three modules: Ionization, Analysis and detection. A LabVIEW system was developed to control the three modules of a mass spectrometer, giving the required signals in a right sequence. Experiments can be carried out by using the …

College Of Engineering Senior Design Competition Spring 2011, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …

College Of Engineering Senior Design Competition Fall 2011, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …

New Construction Builders Challenge: Sealed Attic And High Efficiency Hvac In Central Florida: A Year In Review Monitored Prototypes - Springwater Homes, Florida Solar Energy Center, Carlos Colon

FSEC Energy Research Center®

In 2010 the Florida Solar Energy Center (FSEC), with funding from the Building America program, was involved with a new Builders Challenge builder located in Rockledge, Florida -- Springwater Homes (see figure 1). The newly constructed home in March 2010, features a sealed attic with R-27 roof deck insulation (shown in figure 2). Selection of the HVAC system, an important aspect to achieve high efficiency levels in buildings, ended with one of the highest residential equipment systems available in the U.S., the Nutone IQ Drive (SEER 21). The house was confirmed with a HERS index of 53 using the EnergyGauge …

Classification Of Marine Vessels In A Littoral Environment Using A Novel Training Database, Robert Andrew Lister

Master's Theses - Daytona Beach

Research into object classification has led to the creation of hundreds of databases for use as training sets in object classification algorithms. Datasets made up of thousands of cars, people, boats, faces and everyday objects exist for general classification techniques. However, no commercially available database exists for use with detailed classification and categorization of marine vessels commonly found in littoral environments. This research seeks to fill this void and is the combination of a multi-stage research endeavor designed to provide the missing marine vessel ontology. The first of the two stages performed to date introduces a novel training database called …

How Much Do U.S. University Students Know, And Want To Know, About Sustainability And Green Building? The Findings Of A Survey, And Possible Implications For General Elective Curricula., Jeremy R. Farner

Purdue Polytechnic Masters Theses

Using the survey approach, this investigation examined the attitudes and interest of college students at two universities in different geographic locations within the United States.  Approximately 24,000 students from all disciplines and majors at Weber State University (WSU) in Utah, and 4,000 at Purdue University in Indiana, were invited to participate in a study to determine current knowledge, familiarity, and interest in topics within the sustainability and Green Building educational arena. The goal of this study was to determine what students already know, would like to know, and how much interest there would be in developing …

Capillary Climb Dynamics In The Limits Of Prevailing Capillary And Gravity Force, B. Bijeljic, B. Markicevic, Homayun K. Navaz

Mechanical Engineering Publications

The dynamics of capillary climb of a wetting liquid into a porous medium that is opposed by gravity force is studied numerically. We use the capillary network model, in which an actual porous medium is represented as a network of pores and throats, each following a predefined size distribution function. The liquid potential in the pores along the liquid interface within the network is calculated as a result of capillary and gravity forces. The solution is general, and accounts for changes in the climbing height and climbing velocity. The numerical results for the capillary climb reveal that there are at …

Dynamics Of A Partially Fluid-Filled Sphere, Jeff Hendricks, Taylor W. Killian, Robert A. Klaus, Nick Smith, Tadd T. Truscott

Faculty Publications

We introduce a study on the slosh dynamics of a partially filled elastic sphere. Currently the physical design of fluid-filled containers utilizes clever construction and machinery to mitigate sloshing motions. There are numerous cases that have been observed but we focus on the impact of a sphere under free fall with an initially undisturbed free surface. The study focuses on measurement and simulation of the force distribution between the fluid and the sphere through the use of high-speed imaging and finite element analysis. Using the cavity shape data, a potential flow numerical model is developed that predicts the unsteady forces. …

Analyse Du Comportement Réel Et De L'Optimisation Structurelle Des Cycles De Turbines À Gaz, Alexandru Dobrovicescu, Michel Feidt, Lavinia Grosu, Jim Mcgovern, Georgiana Tirca-Dragomirescu

Conference Papers

L’article présente une étude comparative, basée sur l’analyse exégétique, de l’effet de non prise en considération du comportement réel de l’agent thermique et de l’utilisation des modèles simplifiés pour calculer les performances des cycles de turbines à gaz avec et sans récupération de chaleur. Un intérêt spécial a été réservé au processus de combustion et au transfert de chaleur dans le préchauffeur d’air. La variation des destructions et des pertes d’exergie par rapport à la variation des paramètres fonctionnels est présentée.

Ultrasonic Methods For The Characterization Of Complex Materials And Material Systems: Polymers, Structured Polymers, Soft Tissue And Bone, Charles Landais

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Understanding the characteristics and structure of materials is of importance in proper modeling and effective design of many products. Complex materials such as polymers, structured material systems, or biological materials provide a particular challenge to many of the traditional methods for doing this. In this dissertation I study the use of ultrasonic wave techniques to characterize several complex materials. These include plastically deformed and aged polycarbonate (PC), a structured PC plate with water filled cavities, bovine bone, and an elastomer used as a skin simulant. In each case, this work was part of a larger project that studied different aspects …

Modeling And Finite Element Analysis Methods For The Dynamic Crushing Of Honeycomb Cellular Meso-Structures, Jesse Schultz

All Theses

The effective static mechanical properties, such as the moduli of elasticity and rigidity and Poisson's ratio, of honeycomb cellular meso-structures are capable of control due to variations of their cellular geometry. While the dynamic properties of these structures are a popular topic of research, there is a lack of both consistent modeling methods and generalizations in terms of honeycomb cellular geometry. In order to fill these gaps, this study presents a standard set of methods for the finite element analysis (FEA) of honeycomb cellular materials subject to dynamic loading conditions, as well as illustrates the effects of the cellular geometry …

Airplane Landing Flare-The Last 5 Seconds, Nihad E. Daidzic

Aviation Department Publications

No abstract provided.

Lower Extremity Biomechanics During Weightlifting Exercise Vary Across Joint And Load, Kristof Kipp, Chad Harris, Michelle B. Sabick

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The purpose of this study was to determine the effect of load on lower extremity biomechanics during the pull-phase of the clean. Kinematic and kinetic data of the three joints of the lower extremity were collected while participants performed multiple sets of cleans at three percentages: 65, 75, and 85% of 1-Reptition maximum (RM). General linear models with repeated measures were used to assess the influence of load on angular velocities, net torques, powers, and rates of torque development at the ankle, knee, and hip joint. The results suggest that the biomechanical demands required from the lower extremities change with …

Joule Heating Effects On Electrokinetic Transport In Constriction Microchannels, Sriram Sridharan

All Theses

Microfluidic technology involving multidisciplinary studies including MEMS, chemistry, physics, fluids and heat transfer has been developed into a promising research field in the recent decade. If offers many advantages over conventional laboratory techniques like reduced reagent consumption, faster analysis, easy fabrication and low chemical waste. Microfluidic lab-on-a-chip devices have been used to manipulate cells and particles like sorting, separating, trapping, mixing and lysing. Microfluidic manipulation can be achieved through many methods and insulator based dielectrophoresis (iDEP) is one of the highly used method in the recent years. In iDEP, both DC and AC voltages can be applied to the remote …

Simulation And Validation Of Two-Component Flow In A Void Recirculation System, Oscar Eduardo Daza

Master's Theses

Nuclear power plants rely on the Emergency Core Cooling System (ECCS) to cool down the reactor core in case of an accident. Occasionally, air is entrained into the suction piping of ECCS causing voids that decrease pumping efficiency, and consequently damage the pumps. In an attempt to minimize the amount of voids entering the suction side of the pump in ECCS, a Void Recirculation System (VRS) experiment was conducted for a proof of concept purpose. While many studies have been oriented in studying two-component flow behavior in ECCS, none of them propose a solution to minimize air entrainment. As a …

Characterization Of Fracture Toughness G (Sub C) Of Pvc And Pes Foams, Elio E. Saenz, Leif A. Carlsson, Anette M. Karlsson

Mechanical Engineering Faculty Publications

The fracture behavior of polyvinyl chloride (PVC) and polyethersulfone (PES) foams has been examined using the single-edge notch bend and the double cantilever beam (DCB) tests. PVC foam densities ranging from 45 to 100 kg/m³ and PES foam densities ranging from 60 to 130 kg/m³ were examined. The PVC foams failed in a linear elastic brittle manner, whereas the PES foams displayed much more ductility and substantially larger toughness at a comparable foam density. The cell wall thickness of the PES foams was almost twice the thickness of the PVC foams which may have contributed to the high …

Mechanical Properties Of Pecvd Boron Carbide, Dhairyashil Aher

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

To the best of our knowledge, the mechanical properties of PECVD boron carbide (BC) grown using ortho-carborane as a source molecule have never been investigated before. Therefore, this thesis is an attempt to apply the bulge test and the nanoindentation technique for the mechanical characterization of PECVD BC thin films. Mechanical properties such as the Young’s modulus, hardness and residual stress were investigated. The bulge test system using an interferometry technique to measure the deflection of membrane has been designed. Commercially available LPCVD SiN_x membrane windows were used as a substrate to deposit BC films for the bulge test. …

Theoretical Approach For Error Estimation Of Temperature And Thermal Conductivity In Uranium Dioxide Fuel, Adam John Gerth

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The knowledge of in-reactor thermophysical properties of nuclear fuel rods, which are usually composed of uranium dioxide (UO2) ceramics, is important for the safe design and operation of nuclear power plants. A two thermocouple method can be utilized to determine the thermal conductivity within the fuel rods by measuring rod centerline temperature and cladding temperature. Using this technique, Halden Reactor Project (HRP) has developed a correlation for thermal conductivity of UO2 as a function of temperature and burnup. This correlation for thermal conductivity was extracted from experimental data based on a constant thermal conductivity assumption of the fuel rod. However, …

Connective Complexity Methods For Analysis And Prediction In Engineering Design, James Mathieson

All Theses

Complexity is an aspect of engineering design that is often addressed directly with the principle that 'designs should be simple'. However, such a principle fails to offer an effective means of quantifying the complexity of a given design for comparison and decision making. The measurement of complexity within a specific representations and domains has been well established. However, such measurements are inherently limited in their applicability and not always clear in their implications. This research presents a method of measuring complexity from different engineering representations in a consistent manner and explores the application of these measures.
The development of a …

Fluid Dynamics Of Cell Printing, Ping He

All Dissertations

Cell printing is an emerging technology that uses droplets to deliver cells to desired positions with resolution potentially comparable to the size of single cells. In particular, ink–jet based cell printing technique has been successfully used to build simple bio–constructs and has shown a promise in building complex bio–structures or even organs. Two important issues in ink–jet based cell printing are the moderate survival rate of delicate cells and the limited cell placement resolution. Resolving these issues is critical for the ink–jet based cell printing techniques to realize their full potential.
In this work, we use numerical simulations to reconstruct …

An Experimental And Numerical Study Of Secondary Flows And Film Cooling Effectiveness In A Transonic Cascade, James C. Kullberg

HIM 1990-2015

Experimental tests on a transonic annular rig are time-consuming and expensive, so it is desirable to use experimental results to validate a computational model which can then be used to extract much more information. The purpose of this work is to create a numerical model that can be used to simulate many different scenarios and then to apply these results to experimental data.; In the modern world, gas turbines are widely used in aircraft propulsion and electricity generation. These applications represent a massive use of energy worldwide, so even a very small increase in efficiency would have a significant beneficial …

Gimbaled Permanent Magnet-Based Attitude Control For Pico/Nano-Satellites, Rex Bair

Mechanical Engineering Undergraduate Honors Theses

As man-made satellites grow continually smaller and smaller, new, lower mass, volume, and power solutions must be devised to give these satellites the same performance capabilities as larger satellites. One subsystem that is especially difficult to shrink is the Attitude Determination and Control System (ADACS), which is used to position the satellite in a given orientation with respect to a specific reference frame. This paper explores a novel mechanism which combines both of these functions into one device. A permanent magnet is used in conjunction with the geomagnetic reference frame to provide magnetic torque to change the spacecraft's attitude. By …

Design And Calibration Of A Wind Tunnel Facility For The Study Of Active Flow Control On Wind Turbine Blades, Christopher Paul Walter

Renée Crown University Honors Thesis Projects - All

Our group at Syracuse University has been working under Professor Mark Glauser as part of a wind consortium with the University of Minnesota and United Technologies Research Group. Our component of this project will be to develop a system which can be imbedded in an airfoil which can increase the efficiency of the airfoil. Along with developing this “intelligent blade,” we will also be characterizing the affect our control system will have on aerodynamic noise. To accomplish these goals, Syracuse University’s anechoic jet facility was remodeled to incorporate a wind tunnel within which we could run our experiments. Upon the …

Carbon Nanotube Based Ion Sensitive Field Effect Transistor, Matthew Margis

Mechanical Engineering Undergraduate Honors Theses

Carbon nanotubes (CNTs) have been the subject of much research in the past two decades. Due to their extraordinary mechanical and electrical properties, CNTs are ideal candidates for various sensors and electronic device applications. The purpose of this research is to overcome the difficulties in separating and aligning CNTs so that they can be implemented in an ion sensitive field effect transistor (ISFET). A solution to the alignment process has been presented that involves cutting nano channels on a microelectrode chip with an Atomic Force Microscope (AFM) in order to nanomanipulate the CNTs into the nano channels. Upon successfully cutting …

Tribological Behavior Of Lubricants With And Without Nanoadditives: A Compartive Study, Kevin Carlson

Mechanical Engineering Undergraduate Honors Theses

Nano particle based additives have become a main focal point in the design of new lubricants, in order to better achieve reduction in both friction and wear. Previous research has led to the development of one such lubricant known as NanoGlide® by a company called NanoMech, Inc. The success of this initial lubricant design encouraged the research and potential development of new formulations of nano particle based lubricants by NanoMech, Inc. Using tribological testing, and Scanning Electron Microscopy (SEM), this research analyzed the behavior and performance of three new nano additives (NanoGlide 1, NanoGlide2, and NanoGlide3) in three different lubricant …

Spectral Characterization Of Venusian Surface Mineralogy, Johnathon Conley

Mechanical Engineering Undergraduate Honors Theses

While the atmospheric chemical composition of the Venusian atmosphere has been characterized at length by probes and ground-based equipment, the surface mineralogy of Venus is not yet well understood. The extremely thick atmosphere of Venus shields the surface from direct observation. While radar imaging of the surface reveals surface morphology, surface composition is difficult to characterize at a distance. Observation is also difficult due to the intense temperature (approximately 480°C) and pressure (approximately 90 atm) found on the surface. This has prompted NASA and other institutions around the world to begin planning for new missions to land on the surface …

The Effect Of Axial Conduction On Heat Transfer In A Liquid Microchannel Flow, Kevin D. Cole, Barbaros Çetin

Department of Mechanical and Materials Engineering: Faculty Publications

Analysis is presented for conjugate heat transfer in a parallel-plate microchannel. Axial conduction in the fluid and in the adjacent wall are included. The fluid is a constant property liquid with a fully-developed velocity distribution. The microchannel is heated by a uniform heat flux applied to the outside of the channel wall. The analytic solution is given in the form of integrals by the method of Green’s functions. Quadrature is used to obtain numerical results for the local and average Nusselt number for various flow velocities, heating lengths, wall thicknesses, and wall conductivities. These results have application in the optimal …

The Design, Development, And Optimization Of Variable And Fixed Orifice Dampers With Empirical And Experimental Testing For Implementation In The Railroad Industry, Charles K. Speck

Theses and Dissertations - UTB/UTPA

The work of this thesis details the experimental testing, development, and optimization of the spools and system of the variable orifice damper system. The fixed orifice system was developed from concept, tested, and then redesigned. The experimental testing for the orifice selection directed the optimization and final design for the fixed orifice damper system. The testing focused on the evaluation of pressure drops and flow rate for static testing. The dynamic testing evaluated the displacement rate and force loading. Design, testing, and optimization worked to achieve designed flow rates and pressure drops provided by Amsted Rail based upon simulations. When …